The traffic capacity of networks is expected to increase drastically, from not only a recent increase in network population, but also demands for the delivery of high-definition motion pictures or desire for bidirectional real-time video services typified by a television telephone. With this traffic increase, the power consumption of optical communication networks is also expected to increase drastically (see FIGS. 2 and 3 of Paper 5.5.3, ECOC 2009).
In order to realize a drastic reduction in power consumption even at the peak of such network traffic, research related to optical path networks disclosed in Non-Patent Document 1 and Non-Patent Document 2 has been performed. In these optical path networks, a route that connects a starting point and an ending point is set and secured in advance. Therefore, it is possible to omit electro-optic/optic-electro (OE/EO) conversion using an optical transceiver or routing calculation in anode located in the middle of the path. In addition, an aggregation device of optical transceivers as disclosed in Non-Patent Document 1 and Patent Document 1 is introduced. Through the sharing of the optical transceivers using the aggregation device, it is possible to freely establish the same number of optical paths as the optical transceivers deployed. Such a function can be applied to a network capable of being dynamically reconstructed according to the usage condition of a network.
On the other hand, an application that is required high reliability like electronic commerce and so on is currently used in an optical network, as disclosed in Non-Patent Document 3. Thus, in order to realize the high reliability thereof, a network having no service interruption is required. When a failure occurs, the service interruption time is required to be suppressed to a minimum, for example, to 50 milliseconds (msec) as a criterion.
As an optical transceiver for realizing both such a reduction in power consumption and the high reliability of a network, for example, the following Patent Document 2 and Patent Document 3 are proposed. For example, Patent Document 2 discloses a method in which a power supply unit of an interface modulation unit and a data processing unit which have high power consumption is turned off. In addition, Patent Document 3 discloses a method in which signal energy is minimized while monitoring signal quality between counter transceivers.